1. Field of the Invention
This invention relates to packages, and more particularly to packages resealable after opening.
2. Description of the Prior Art
The use of paper, cellophane and other materials for construcion of packages which are capable of being easily torn is common in the art. These expensive packaging materials are popular with manufacturers for their ease of use, as well as for economic reasons. Many packages made of such materials are not reclosable or resealable. Of those that reclose (such as cereal boxes), there is reclosing but not resealing. Many food items (such as candies, cookies or potato chips) are packaged in tearable materials, but they are not capable of resealing. In addition to the problem of resealing, packages made of tearable materials often tear farther than desired and become incapable of being used.
To solve that problem, tear strips have been used with heat sealed polyfilm packages. The tear strips, however, limit the area of opening. Some package designs, for example A. Schmermund (Germany Pat. No. 1,112,691), slits a sheet of wrappings, inserts a tearstrip underneath the slit, slits the tearstrip and then joins the open edges by a strip of adhesive, the adhesive holding the original slit closed until initial opening. Platt in U.S. Pat. No. 3,279,331 shows a variety of flexible containers which reseal by use of adhesive on an inwardly folded package lip. Hughes in U.S. Pat. No. 2,949,370 provides two separate seals, one permanent and broken upon original opening of the package, and another for resealing the package, the resealing provided by a segment of pressure sensitive reseal material being joined to itself.
As the technology of packaging and adhesives improves, new, easier and more efficient package closures must be developed which will not only be economic, but which will reseal easily.
Additionally, because of recent problems with package tampering, the consumer has shown a desire to be able to determine if a package or its contents have been contaminated. This is a particular problem for producers of goods sold in resealable packages.
There is, therefore, a need for new and improved resealable containers which are easy to open and reclose, which reseal efficiently, and which offer proof of tampering with the seal.